Firearms, including pistols, rifles and shotguns, are used in a variety of sporting competitions around the country wherein various skills of the competitor are matched against both another opponent and the clock. Similarly, firearms are a staple piece of equipment for hunters, law enforcement and military personnel, worldwide. Key to success in competition, in the field, and on the battlefield is the ability to handle and fire a firearm quickly and skillfully. Thus, the number of rounds of ammunition any particular weapon can fire before it needs to be reloaded is of significant interest. Further, in certain competitive events, as well as in law enforcement and military applications, the ability to reload a weapon quickly and accurately is a prized quality.
Weapon designers constantly strive to decrease the time needed to reload a firearm. It is axiomatic that a competitor (or soldier) who spends less time reloading his weapon will have an advantage over a similarly situated competitor (or enemy soldier) who spends more time reloading his weapon. With regard to military and law enforcement applications, the advantages of a quick-release magazine are obvious. The faster an empty magazine can be released and a fully-loaded magazine inserted into the weapon, the faster a soldier or police officer can protect himself or another.
In many types of automatic, semi-automatic, bolt-action, and lever-action firearms (e.g., pistols, rifles, shotguns, and the like), several rounds of ammunition (anywhere from two to several hundred or more) are stored in a spring-loaded magazine. While the physical dimensions of magazines differ among manufacturers, models and calibers, all firearm magazines share certain critical features. Notably, all magazines include a housing in which the rounds are stored and held until needed. The housing includes an open top which is dimensioned and configured to feed the rounds of ammunition smoothly into the receiver of the corresponding firearm. The outer dimensions of the housing are configured to matingly and releasably engage a corresponding magazine bay and magazine locking/releasing mechanism of a corresponding firearm. Disposed inside the housing, and anchored at the bottom of the magazine, is spring that is biased to urge the rounds of ammunition toward the top of the magazine. In this fashion, as the top-most round in the magazine is extracted and fired (by the action of the firearm), a new round is urged into the top-most position and is ready to be loaded into the receiver of the firearm. Small-capacity magazines for most pistols and center-fire rifles are roughly rectangular in appearance, while large-capacity magazines are normally curved to save space. Certain types of long guns, such as many rimfire .22 caliber rifles, use tubular magazines that feed the rounds axially, rather than transversely. As used herein, the term “magazine” encompasses all such magazines, without limitation.
In pistols and certain types of carbines (short-barreled rifles), the magazine bay is located in the pistol grip of the firearm. In most hunting long guns, the magazine bay is located forward of the trigger assembly, in or near the “forearm” area of the weapon. In certain tactical military weapons, the magazine is located behind the trigger assembly in the butt of the weapon. (This type of firearm is often called a “bullpup,” a design that yields a very compact weapon.) Firearms with a tubular magazine can have the magazine disposed within either the butt of the weapon or in the forearm of the weapon.
The Colt model M1911 pistol and its magazine are a perfect example of a typical semi-automatic pistol design. The model M1911 pistol remains a very popular and widely copied semi-automatic pistol. This storied pistol was designed by John M. Browning and was the standard-issue sidearm for U.S. military forces from 1911 until 1985 (hence the designation “M” for military and the first year of its mass production). The Colt M1911 was originally chambered in .45 ACP. The design proved an instant success. Roughly 2.7 million M1911s were produced by the close of World War I. In the period between the world wars, the design was modified slightly and the modified version was given the model designation 1911A1. During this period, more than 20 different manufacturers, worldwide, were licensed to produce this model, in a wide range of different calibers. U.S. manufacturers, including Colt, Remington, Ithaca, Union Switch and Signal, and The Singer Sewing Machine Company, combined to produce more than 2 million model 1911A1 pistols in the war years 1941 to 1945. The 1911 design, long since “off-patent”, has been widely copied and modified.
The magazine for a 1911-style pistol features a roughly rectangular housing with walls that narrow in width at the top. The bottom of the housing is open and terminates in an outwardly-directed lip or flange. A floor plate is attached to the flange at the lower end of the housing, thereby closing off the bottom end of the magazine. A butt pad or “slam pad” is also attached to the flange at the lower end of the housing, and serves to cushion the lower end of the housing when the magazine is forcefully inserted into the firearm (which is often the case). A leaf spring is disposed within the lower end of the housing to urge the rounds loaded within the magazine toward the top. When the magazine is empty, a release button on the pistol is pressed, and the magazine is grasped at its lower end by the user's free hand and separated from the weapon.
The prior art is replete with efforts to decrease the time needed for reloading. The most simple route, of course, is to increase the capacity of the magazine (while conforming to the law and the standards of any given competition). Many countries, however, place strict limits on magazine capacities for firearms sold into the civilian markets. After-market, large-capacity magazines are widely available in the United States. But a larger magazine also significantly increases the weight of the weapon when the magazine is fully loaded. The added weight of additional rounds compromises the speed of handling the weapon and the added weight can also compromise the accuracy of the weapon. Large capacity magazines also tend to misfeed more often than smaller capacity magazines. Thus, a larger capacity is not an ideal solution to minimizing the time needed to reload a firearm.